Combined immunotherapy for metastatic triple-negative breast cancer based on PD-1/PD-L1 immune checkpoint blocking

Metastatic triple negative breast cancer is not only the worst prognosis and the strongest invasive subtype of breast cancer, but also the most immunogenic subtype, so it can be reasonably predicted that immunotherapy can play a positive role in the treatment of metastatic triple negative breast cancer. However, the effect of using PD-1/PD-L1 immune checkpoint inhibitors alone is not very ideal. In recent years, the regimen of combined therapy has been emerging. This article reviews the application of combined immunotherapy based on PD-1/PD-L1 inhibitors in metastatic triple negative breast cancer, including chemotherapy, targeted therapy, radiotherapy and oncolytic virus therapy. The problems existing in combined therapy and the possibility of future research are discussed, which can provide a reference for the selection of treatment options for patients with metastatic triple negative breast cancer in different situations.